GB503503A - Improvements in and relating to elastic strands - Google Patents

Abstract

503,503. Elastic threads; indiarubber compositions. LILLEY, S. C. Oct: 6, 1937, Nos. 27078 and 27079. Convention dates, Oct. 20, 1936 and July 22, 1937. [Class 120 (iii)] [Also in Group V] Elastic threads or strands are secured to covering strands or to other strands with which they are associated in a fabric, by applying a thermoplastic adhesive-forming material to the elastic strands and, while the adhesive-forming material is in a non-liquid and unsoftened state, covering the elastic strands or incorporating them in a fabric and then subjecting the elastic strands to the action of heat to soften the adhesive-forming material and cause it to adhere the covering strands or the other strands to the elastic strands. As shown in Fig. 3, the thread 11 is formed by cutting a sheet of rubber, which has been coated on at least one face with the adhesive 12, into strips and the thread so formed may be used in a fabric or be covered by strands of a textile material. In the thread shown in Fig. 7 the thermoplastic adhesive material is in the form of a ribbon 21 applied as a helical wrapping and the covering material 22 is preferably applied in a direction opposite to that of the material 21. The covering material may be formed from composite strands helically wrapped around the core and each comprising one or more filaments of thermoplastic adhesive material and one or more filaments of cotton &c. The adhesive-forming material may also be applied to the elastic core as a coating or as ribbons applied longitudinally of the core. The core is preferably formed from a mix of rubber 100 parts, sulphur 3<2>/3 parts, stearic acid 1 part, symmetrical di-#-naphthyl-pphenylenediamine 1 part, zinc sulphide 5 parts, phenylhydrazine ¢ part, 90 per cent zinc salt of mercaptobenzothiazole and 15 per cent di-o-tolylguanidine 1 part, zinc oxide 5 parts, and polymethylacrylic methyl ester 20 parts. The thermoplastic adhesive material is preferably formed from a mixture of blended rubber 100 parts, zinc oxide 5 parts, zinc sulphide 5 parts, stearic acid 3 parts, sulphur 3¢ parts, mercaptobenzothiazole 1¢ parts and symmetrical di- #-naphthyl-p-phenylenediamine 1 part; other adhesives which may be used are formed from a mixture of rubber 100 parts with dibutylammonium oleate 3 parts or metatoluenediamine 1 part or di-penta-methylenethiuramtetra sulphide 3 parts, or a fatty anhydride (stearic acid or the like) 3 parts. Balata, guttapercha or polymethylacrylate may also be used.